Steam-generator.



' No. 709,37l. Patented sept. I6, |902.

P. sToLTz.. STEAM GENERATOR.

(Application filed Det. 26, 1901.)

2 Sheets--Sheet l.

(No Model.)

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ATENT @Prion PETER S'IOLTZ, OF BERLIN, GERMANY.

STEAM-G EN ERATOR.

` SPECIFICATION forming part of Letters Patent No. 709,371, dated September 16, 1902.

' Application tied october 26.1901. sentimenten. (remodel.)

To a/ZZ whom,` it may concern:

Be it known that I, PETER STOLTZ,engineer, a subject of the Emperor of Germany, residing at 138 Friedrichstrasse, Berlin, in the 'Empire of Germany, have invented certain new anduseful Improvements Relating to 1 Steam-Generators, of which the following is a specification. l

This invention relates to steam-generators `having several groups of tubes connected together, whereby the adj acently-disposed lonconstructinga steam-generator in accordance with this invention several such elements of groups of tubes are disposed side by side and I'Ieretofore in constructing steam-generators of this class the tube ends have been secured in chambers; but with this method of construction, however, it is necessary to stiffen the said chambers by stay-bars or stay-bolts, so as to avoid excessive stress on the connecting-joints of the tubes. l

In my improved steam-generator the walls of the longitudinaltubes and `of the transe verse passages which connect saidllongitudi- `nal tubes in each group with each other form a solid whole, thereby avoiding the use of theabove-mentioned stay-bars, while at the same time obviating the disadvantages due to the fixing of thelongitudinal `tribes in the chambers. `By avoiding said fixing o f the longitudinal tubes theycan be placed close l together, and thus provide a large heatingsurface within a small space and increase the proportion of the heating area to the volume The tubes may be disposed so close together as to have combined Walls :at the adjacent parts, thereby preventing distortion of the tubes `and rendering the Wholeboiler compact and light,while, furthermore, the resistance of the tube groups is increased and greaterl rigidity imparted to the generator.- The separate groups of tubes can readily be changed, 'and cleaning of the same is greatly facilitated. It' the first formation of the group of tubes is effected byexternal mechanical operation-for instance, by rolling, pressing, forging, &c.-the quality of the material is improved by the compression, thereby increasing the resistance and safety of working of the generator. This type of steam-generator is suitable for very high steam-pressures and in particular for motorvehicles and motor-boats.

In order that rnyinvention maybe readily understood and carried into practice, I Will now proceed to describe the same fully with reference to the accompanying drawings,`in

Which- Y Figure l shows a front elevation of agroup of tubes embodying this invention and preferably made by rolling. Fig. 2 is a plan of the same with partly-bored channels. Fig..3 is an edge View. Figs. 4, and 5 show a front and side elevation, respectively, of a steamgenerator, partly in section, which is composed of groups of tubes as shown in Figs. 1 to 3. Figs. 6 and 7 show a longitudinal section and a side elevation, respectively, partly in section. Figs. 8 to 10 show a modification, in which Fig. 8 shows the upper portion of a group of tubes in side elevation, Fig. 9 shows aplau, and Fig. 10 a cross-section with partlybored channels. Figs. 1l and 12 show a front elevation and a side elevation, partly in section, of a steam-generator composed of groups of tubespas shown in Figs. 8 to 10. Figs. 13 and ltshoW several forms of construction of the evaporating-chambers.

Figs. l to 3 show the manner of constructing or forming a group of tribes of' a single rolled piece. The shape of the rolled piece is shown in Fig. 2, and it is only necessary to cut the desired length from the piece from the rolling-mill, Fig. l. already the required finished external form, in which the longitudinal tubes afstand out as ribs. The tubes Ct are connected at their adjacent longitudinal parts by narrow webs b. After the production of the rolled piece, Fig. l, the successive longitudinal channels g, Fig. 2, are made by boring. The tubes This part thus has thus formed are thus connected together at the upper andY lower ends by cross-passages,

' formed by boring at h through all 'the webs b, as indicated by dotted lines in Fig. l. To Venable these cross-passages to be made, it is necessary to have the webs b between the adjacent tubes at y, Fig. 2, sufficiently thick.

The longitudinal rib n: may be utilized for .end, and this may be effected, as shown in Fig. 13,- by vnot boring the hole g right through the tubesa, but leaving them closed at u, so that no separate means for closingis required at such end. The opening o atthe other end of the tube may then be closed by a screw-stopperm or in any other convenient means.

If it is desired tovobtain a Amore favorable heating effect by providing annular Water and steam chambers, this may be carried out as shown in Fig. 14. In this case the tube a is bored out for its entire length, andinto the tube a is theninserted a second tube iat s and j, so as to form a water and steam space of annular section. ,The manner of fixing the tube 'i may be such as to enable it to be readily removed for the purpose of cleaning the interior of the steam-generator. For this purpose the tube t' inthis arrangement is provided with screw-threads at one end jand is screwed into the screw-threaded mouth of the tube a. The other end may be secured'in the tube a by wedging, burring, or other suitable manner. In the arrangement shown in Fig. 14 the vaporizing-chamber of annular section is thus formed between the tubes 1I and a. The

spaces thus formed communicate with each other through the passages h. Owing to the fact that the tubes t and the tubes a are not secured to separate communication chambers, all the tubes of eachgroup may be disposed close together, with their axes as shown in Fig. 2. Y By having the tubes a so close together, with a single or common wall between them, a greater stiness of all the tubes a, combined with greater strength, is obtained, while, further, the largest possible internal space for the steam-generator is provided in proportion to the entire space occu pied by the said generator. Moreover, by the manner of securing the inner tubes t', as shownin Fig.

14, the jointsthereot' are not subjected to pull or pressure, while the rolled or forged shaped part, which contains the tubes g h, forms a single structure which receives all the stresses of pull and pressure from the generation of the steam without communicating said stress to the joints. For this reason the longitudinal stays required for ordinary steam-generators composed of tube groups and which are placed lengthwise to the tubes ct can be dispensed with. In consequence of the increased resistance of the tube element formed by mechanical operation it will be possible to reduce the wall thicknesses without weakening the safety factor of working, andthus the eiciency ot' the boiler is raised. All these conditions coperate to produce advantaj,v geous proportions between internal space, ex-

ternal space, water volume, and weight.

The elements of tubegroups thus manu,y f

factured are mounted together to` form a steam-generatoras follows: In the arrangethe lower water-channel p or upper steam--l` channel r. The tube-group elements thus connected one with another may inv motor cars, for example, be engaged and fixed in a frame.

,In order to enable steam-generators con-V structed according to my improved arrangement to have a minimum of weightand also an effective connection betweenthe variousl tubes, the tube groups may be further bored withcross-channels w, as shown in Figs..6 i and 7, and the outer holes may afterward bey l closed by screw-plugs Z or the like. By this Y arrangementof cross-passages 4w the Weightf of the steam-generator is reduced, while at the same time the water circulation is greatly increased.

The tube element shown in Figs. 8 to 10 may be produced by forging or stamping in dies. In this form of construction there are provided special enlargements d d for the passages forming the cross-channels h h. The tubes may be completely separate or they may be connected by their adjacent parts. They may, as previously described, be con'- nected together by small longitudinal Webs b. The stamped or forged section may advantageously be formedI at the same time with the flanges flat the ends of the enlargements d and with the screw-threaded connections t at the other ends for mounting the steam-generator together.

Figs. 1l and 12 show a steam-generator composed of such tube group elements, whereby the dan ges f are connected by means of bolts o with the lower'water-,channel pand the upper steam-channel r, respectively.

The details may be variously modified, and the cross-section of the various tube element-s may 'also be altered. The tubes a, may externally be formed with prismatical walls or with ribs, and-the arrangement for connecting the several tube elements with each other may be executedin various manners. It is always essential that each tube group or their longitudinal and cross passages should form a complete structu re, whereby the tube groups first receive their external form by anyappropriate means, while both the tubes, as also the channels connecting the same, are produced by boring.

What I claim, and desire to secure by Letters Patent of the United States, is-

1. A steam-generator, comprising VaporizlOO IIO

` ing-chambers, each consisting of a single plate of metal provided with oppositely-disposed pairs offconvex ribs extending `from edge to`edge of saidplate, and with longitudinalpassages concentricwith` said convex i ribs and extending centrally through said plate substantially from edge toedge thereof,

and also provided with short passages l connecting saidI longitudinal passages. "Io

` 2. A steamf'generator,comprising Vaporizing-chambers, each consistingof a single `plate of metal provided with oppositely-disposed pairs of convex ribs extending longitul dinally from edge to edge of said plate, and

with longitudinal cylindrical passages concentric with said convex ribs, said plate be ingfurther `provided with means for allowing i intercommunication `between said longitudi- A l nal passages atlpoints adjacent to the ends "20, i

thereof. i

3. A steam-generator, comprising Vaporiz-` ing-chambers each consistingof a single-` plate of metal provided with oppositely-dis-` i" z` posed pairs of convex-ribs integrally con# g `nected together,and also provided with lonxgitudinalpassages disposed closely together, "isaidlongitnd'inal passages being connected together by short passages extending directly through the substance of the plate, whereby the tendency toward leakage is greatly lessduced. p

`4. A steam-generator, comprising Vaporizing-chambers each consisting of aplate of `metal provided with longitudinal passages exi tending throughout the substance of said plate substantially from edge to edge thereof, `and a-plurality of hollow tubes disposed within said longitudinal lpassages and fitted steam-tight into therespective ends thereof, said hollow tubes at points intermediate of g said ends being concentrically spaced within said passages, thereby forming steam-spacesg each of a general tubular form, said platebeing further provided with"` `means'for maintaining communication between said steamspaces.

l ened and a structure of great strength is pro-` p In testimony whereof I have hereunto set i my hand, in presence of two subscribing Wita nesses, this 12th day of October, 1901.

` t PETER STOLTZ.

Witnesses:

WOLDEMAR HAUPT, HENRY HASPER. 

